This letter supplements KRC’s comments and request for a public notice and comment period regarding the above-referenced application for authorization to temporarily land-dispose of partially treated sewage sludge in unlined trenches on formerly mined land in Nortonville, Kentucky.
I understand from news reports that a public comment period will be provided concerning the proposal, and that the agency is undertaking technical review of the application. I am writing to underscore the significant concerns that KRC believes to attend the proposal.
As noted in KRC’s earlier letter, the organization supports, under properly controlled circumstances, the beneficial reuse of composted and treated sludges as an alternative to permanent land disposal of those materials. As you are well aware, however, the pathogens, odors, and potential accumulation of high concentrations of heavy metals and other entrained organics in sewage sludges from centralized wastewater treatment plants, demands that at all phases of management, storage, transportation, treatment and disposal of the wastes and conversion into useable “product,” the potential for creation of gaseous, liquid and solid wastes, and the possibility of nuisance conditions, be evaluated and addressed.
From what has been provided in the application that has been filed with the Division of Waste Management, KRC does not believe that the proposal demonstrates that human health and the environment will be adequately protected during storage an “treatment” of the sludges and in final disposition of the material.
KRC has these specific concerns, some of which were addressed briefly in the initial letter:
1. Prior to engaging in further technical review of the proposal, your agency must first determine whether the application has properly classified the proposed activity as one of “storage and treatment” of a special waste eligible for a registered permit-by-rule. KRC believes, for the reasons stated below, that this proposed activity is ineligible for a “registered permit by rule” and instead must be considered either a special waste landfill or a research, development and demonstration permit, subject to full permitting, design, operational, closure and bonding requirements.
The registered permit-by-rule, which KRC has criticized as “drive-by permitting,” is a problematic mechanism that has and continues to result in the possibility of approval of “beneficial reuses” and treatment of special wastes that undermanage the wastes in terms of their potential to adversely affect the environment. The substitution of the after-the-fact possibility of bumping a registered permit-by-rule into an individual permit based on demonstrated environmental damage, is wasteful and harmful as a matter of public policy and substitutes an inefficient enforcement-based strategy for thorough technical permit review in advance of approval. This proposal is yet another example of why the agency should prioritize the reevaluation and overhaul of the “permit-by-rule” and “registered permit-by-rule” mechanisms, and to increase the technical demonstrations and performance obligations of applicants seeking to “beneficially reuse” potentially problem wastes such as sewage sludges and coal combustion ash.
KRC harbors serious doubts as to whether the proposal to temporarily dump 500 tons per day of raw sludges into unlined trenches on previously mined land, to cover the sludges with soil and then excavate them months later, constitutes “treatment” within the meaning of the regulations. Despite searching, KRC has not found any literature recommending an anaerobic digestion process for sewage sludges that uses unlined in-ground digestion rather than contained vessels to anaerobically digest sewage sludges.
State solid waste regulations express a basic distinction between management of wastes in order to allow for decomposition and subsequent beneficial reuse of the waste and simply allowing natural decay. “Composting” is defined under 401 KAR 45:010 Section 1(5) to mean the “process by which biological decomposition of organic special waste is carried out under controlled aerobic conditions, and which stabilizes the organic fraction into a material that can easily and safely be stored, handled and used in an environmentally acceptable manner.
By contrast, the state regulations, (which recognize that composting may include a process that creates an anaerobic zone with in the composting material), specifically disallow “simple exposure of special waste under uncontrolled conditions resulting in natural decay.”
The proposed “treatment” method here is uncontrolled except that it will occur in a dug trench, since the generation of leachate and rate of generation and capture of resulting gas is not proposed to be managed, and the material is simply to be dumped into a trench in order to allow for “natural decay” under anaerobic conditions. As with composting material in order to decompose the active wastes into stable material under aerobic conditions, the anaerobic decomposition of the waste must be demonstrated to be controlled, and the resulting organic fraction shown to be stable and safe for use, both to those involved in the management of the decomposition and resulting material, and those who may encounter the waste. The proposed management method is more akin to landfilling followed by excavation of the landfilled material after natural decay has occurred for a period of time, than it is to controlled treatment, and should be permitted with the full array of precautions attendant to in-ground placement of biologically and chemically active wastes.
Additionally, given the apparently unproven nature of this technology, and given the historical problems in the management of this waste stream both in Tennessee and in Kentucky, the use of a registered-permit by rule would appear inappropriate even if this activity is considered as “treatment” within the meaning of 401 KAR 45:070.
Unless the applicant can provide data demonstrating that the same technology (if the approach can be properly called a technology) has been employed elsewhere and that all of the air emissions, land and water contamination and nuisance potential have been assessed and shown to be within appropriate limits, this activity must be permitted if at all as a “research, development and demonstration permit” under 401 KAR 45:135. This category of special waste permits, according to the regulations “is a category of special waste or facility permit to demonstrate unproven technology [.]”
The proposed activity should be subject to much more rigorous review, waste characterization, transport, storage and handling, placement, excavation, and in-ground management controls in order to assure protection of human health and the environment, and this category is better suited to tailoring of such conditions and requiring such additional information. Additionally, individual permitting would allow for proper calculation of closure and post-closure bonds since the unlined nature of the proposed “treatment” trenches and biologically and chemically active nature of the wastes all but assures that there will be migration of contaminants necessitating future corrective action and long-term management.
For each and all of these reasons, KRC respectfully requests that the agency return the application and request the applicant to submit the application as a special waste landfill or a research, demonstration and development permit, addressing these concerns and providing appropriate public comment and notice to local government and citizenry.
2. Additional technical concerns with the application
In addition to the fundamental question of whether the activity constitutes “treatment” or whether, as KRC believes, it should be properly classified as either a temporary landfill or a research, development or demonstration activity, KRC has additional concerns regarding gaps in information provided in the application, which prevent your agency from making a reasoned determination by your agency that the environmental performance standards will be met in the management of the material.
The proposal to “treat” the material in order to reduce pathogens through dumping of the material in an unlined trench and covering the material for a period of time, followed by excavation and landspreading of the material, will likely result in off-site migration of leachate containing constitutents of the sludge material. Lacking any run-on controls and lacking any mechanism to avoid rainfall saturating the material (which is already at a high moisture content), the infiltration of direct rainfall and rainfall in the vadose zone surrounding the below-grade trenches will result in likely creation of leachate that will carry constituents into the fractured zone beneath the trenches.
Leaving aside, for the moment, the significant legal and technical questions about whether this in-ground placement of sludge material is “treatment”, if such a placement is allowed without a composite liner, leachate collection and groundwater monitoring, then the applicant must demonstrate that the groundwater protection standards in the state environmental performance standards can be met at the point of compliance for all constitutents, through comprehensive characterization of the waste.
TCLP analysis, which is a short-term dilute acid test intended to replicate MSW landfill disposal conditions and to demonstrate leachability of metals and benzene under such conditions, does not provide a comprehensive or necessarily appropriate test protocol to enable the agency to predict what constitutents will leach from this waste during the “in-ground treatment” of the waste. Additional analysis is advisable to assure that under the proposed "treatment" conditions and under proposed beneficial reuse conditions (i.e. when landspread), no organic or metals of concern will leach at levels of concern. TCLP testing does not, for example, provide information on long-term leaching potential of sludges used for soil amendments. Neutral-water analysis and over a longer period of time, until the various constituents reach equilibrium should be used to augment TCLP testing. Additionally, the pH characteristics of the soil, the rainfall, and the run-on that the sludge will encounter at the "treatment" site should be considered, as should the affect (if any) on the anticipated changes in temperature on the leaching potential of the organics and metals in the sludge.
Once the waste has been thoroughly characterized under proposed storage, “treatment” and landspreading conditions, the hydrogeology of the proposed “treatment” site must be evaluated. Since there is no liner or leachate collection system proposed, analysis using the HELP or other appropriate landfill leachate analysis should be conducted, assuming no liner and 100% leachate migration. The applicant must provide sufficient information concerning the unique hydrogeology of the surrounding area, and cannot rely on generalized GQ maps since the area has been previously mined and the natural geology has been altered. The area is likely to be more highly fractured than undisturbed strata in the region, increasing the likelihood that the primary mechanism of groundwater flow will be secondary media (fracture) flow, so that leachate will migrate more rapidly and with less attenuation of contaminants than would otherwise be expected. Given the presence of the regional Nortonville aquifer and the significance of that aquifer for the community and for future economic development, thorough characterization of the hydrogeology is needed using an appropriate array of core sampling and groundwater monitoring wells to characterize the location, quality and quantity of groundwater in the area.
The potential for generation of explosive or harmful gases has not been adequately discussed. Among other byproducts, anaerobic digestion produces methane gas – an odorless gas that within a certain concentration range, is explosive, and which can injure public health. The amount of gas anticipated to be produced, and the fate and transport mechanisms for the gas, are not identified. In a properly-contained anaerobic digestion unit, the waste gas can be captured and utilized or treated. In this proposal, it would appear that the gas will migrate into the surrounding vadose zone and through the soil layer, off-gassing methane in a manner that could cause explosive or dangerous concentration of the gas.
In closing, the Council, on behalf of numerous members in Hopkins County, respectfully requests that the application be returned as being ineligible for a special waste registered permit-by-rule.
Tom FitzGerald Director